Slushing scraper



p 1967 NIA. DOBBIE ETAL 3,340,628

SLUSHING SCRAPER Filed Feb. e, 1964 Y 5 Sheets-Sheet 1 BMMQM PATENTAGENT INWW V f 0 My 7,24/(9/1/ p 1967 N. A. DOBBIE ETAL 3,340,628

SLUSHING SCRAPER Filed Feb. 6, 1964 5 Sheets-Sheet 2 Sept. 12, 1967 N.A. DOBBIE ETAL SLUSHING SGRAPER Sheets-Sheet 3 Filed Feb. 6, 1964.

PATENT AGENT Sept. 12, 1967 N. A. DOBBIE ETAL SLUSHING SC RAPER 5Sheets-Sheet 4 Filed Feb.

PAQIY QNCAGENT- Sept. 12, 1967 N. A. DOBBIE ETAL SLUSHING SCRAPER 5Sheets-Sheet 5 Filed Feb. 6, 1964 PA'LEXILNAGENI United States Patent3,340,628 SLUSHING SCRAPER Norman A. Dobbie and John A. Wilson, Orillia,Ontario, Canada, assignors to Fahralloy Canada Limited, Orillia,Ontario, Canada Filed Feb. 6, 1964, Ser. No. 342,883 Claims priority,application Canada, Jan. 28, 1964, 894,278 22 Claims. (Cl. 37-147) Thisinvention relates to a slushing scraper, and more particularly, to aslushing scraper of the type having arms detachably connected to theblade.

There are some slushing scrapers presently being used in which the armsare cast integral with or are permanently welded to the blade. However,such scrapers are not popular since they cannot be dismantled forconvenient transportation underground. In another type of scraper incommon use today, one or more bolts are used to attach each arm to theblade. The types utilizing a bolt connection are not entirelysatisfactory since after the scraper has been in service for a period oftime, the nuts frequently become frozen on the bolts, making the removalof bolts for dismantling purposes extremely difficult. Moreover, it hasbeen found that some of the bolts tend to loosen or stretch in service,resulting in an expensive maintenance problem, and when very loose, in asubstandard scraping operation.

It is an object of the present invention to provide an improved slushingscraper having a connecting means between the arms and the blade whichpermits the arms to be readily but soundly connected to the blade and tobe easily disconnected from the blade even after a long period ofservice.

According to the present invention, there is provided a blade, a pair ofarms, the blade and arms having integral interlocking sections which fittogether as the front end portions of the arms are brought togetherduring assembly of the scraper, and a clamping fixture for holding thefront end portions of the arms together. The blade has a fronttransverse surface and a first interlocking section integrally formed ateach end thereof, and the arms each have a rear end portion having asecond interlocking section formed integrally therewith. Each of thefirst interlocking sections are engageable with one of the secondinterlocking sections to provide two pairs of interlocking sections forlocking the blade and arms together. Each of the pair of interlockingsections defines interengageable fulcrum surfaces one each on theinterlocking sections, and each pair of sections defines shoulder meansincluding a plurality of mutually angular shoulders on one section ofthe pair, the other section of the pair of sections having shoulderengaging surfaces, each of the shoulder engaging surfaces beingsimultaneously engageable with one of the shoulders coincident withengagement of the fulcrum surfaces to constitute an interlock positionin which engagement of the shoulders with the shoulder engaging surfacesprevents relative movement of the sections of the pair in any directionperpendicular to the front surface of the blade. The shoulder meansincludes a lug on one of the 'sections of the pair and a lug engagingwall on the other section of the pair for engagement with the lug in theinterlock position. The lug and the wall are angularly disposed relativeto the front surface of the blade for preventing movement of the secondsection in the interlock position in a direction parallel to the frontsurface of the blade. Each arm has a first position in which theshoulder means is freely movable into and out of engagement with theshoulder engaging surfaces and the lug is freely movable towards andaway from the wall and a second position coinciding with the "iceinterlocking position. The front end portions of the arms are injuxtaposed relation in the second position and the clamping means holdsthe front end portions together to thereby hold the fulcrum surfaces inengagement, the shoulder means in engagement with the shoulder engagingsurfaces and the lug in engagement with the lug engaging wall.

In the drawings which show certain embodiments of the invention by wayof example:

FIGURE 1 is a front perspective view of one embodiment of a slushingscraper according to the present invention;

FIGURE 2 is a fragmentary perspective view of the slushing blade of theembodiment of FIGURE 1, the arm being removed for the sake of clarity;

FIGURE 3 is a fragmentary perspective view of the arm of the embodimentof the slushing scraper of FIG- URE 1, showing the rear end portionthereof;

FIGURE 4 is a cross-sectional view through the connection of the arm andblade of the embodiment of FIGURE 1, taken along the line IV-lV ofFIGURE 1;

FIGURE 5 is a fragmentary rear perspective view of another embodiment ofthe invention;

FIGURE 6 is a fragmentary rear perspective view similar to FIGURE 5 butwith the arm removed for the sake of clarity;

FIGURE 7 is a fragmentary side view of the arm of the embodiment shownin FIGURE 5 showing the rear end portion thereof;

FIGURE 8 is a cross sectional view through the connection of the arm andblade of the embodiment shown in FIGURE 5;

FIGURE 9 is a fragmentary rear perspective view of still anotherembodiment of the invention;

FIGURE 10 is a fragmentary rear perspective view similar to FIGURE 9 butwith the arm removed for the sake of clarity;

FIGURE 11 is a fragmentary side view of the arm of the embodiment shownin FIGURE 9 showing the rear portion thereof;

FIGURE 12 is a rear view of the arm shown in FIG- URES 9 and 11;

FIGURE 13 is a cross-sectional view through the connection of the armand blade of the embodiment shown in FIGURE 9;

FIGURE 14 is a fragmentary rear perspective view of yet anotherembodiment of the invention;

FIGURE 15 is a fragmentary rear view of the embodiment shown in FIGURE14;

FIGURE 16 is a cross-sectional view through the connection of the armand blade taken along the line XVI XVI of FIGURE 15;

FIGURE 17 is a fragmentary rear perspective view of yet anotherembodiment of the invention;

FIGURE 18 is a fragmentary end view of the blade of the embodiment shownin FIGURE 17 but with the arm removed;

FIGURE 19 is a fragmentary side view of the arm in the embodiment shownin FIGURE 17 showing the rear end portion thereof; and

FIGURE 20 is a cross-sectional view through the connection of the armand blade taken along the line XX XX of FIGURE 17.

Referring now to FIGURE 1, reference character 30 denotes generally theslushing scraper which includes a blade member 31, a pair of arm members32, 32 detachably secured to the blade member 31, and clamping means 33for holding the forward ends of the arm members 32, 32 together. It isto be understood that the blade member as used herein is meant toinclude the item which is commonly called back plate or body in theindustry.

The blade member in vertical cross-section is of opened U-shape having acentral curved portion and contiguous leg portions 34, 34 so that theblade member has a convex back face 35 and a concave front face 36.

The side edges presented along the outer ends of the contiguous legportions 34, 34 provide a pair of forwardly projecting scraping edges37, 37. The scraping edges 37, 37 are preferably symmetrically disposedon opposite sides of a line bisecting the central curved portion of theblade. The scraping edges 37, 37 may both be plain edges, or they mayboth be toothed, or one may be toothed and one plain as shown in FIGURESl and 2, depending on the requirements of the mining operation.

The blade member 31, which terminates at opposite flat end edge surfaces40, 40, has an interlocking section 38 formed integrally at each end.The front face of the blade member has at both ends a pair of beveledgrooves 41, 41 (see FIGURE 2). The grooves 41, 41 are also disposedsymmetrically on opposite sides of a line bisecting the central curvedportion of the blade, and each groove 41 has an inner surface 42slanting rearwardly from the front face of the blade to the end edgesurface 40. Each end edge surface 40 has a hook-like member or lug 43standing outwardly from the end edge surface 40 and projectingrearwardly. The lug 43 has a beveled forward edge surface 44 spacedforwardly from the back face 35 of the blade member 31 and slantingrearwardly away from the edge surface 40. The lug 43 has substantiallyparallel side edges 45, 45 spaced equally on opposite sides of a linebisecting the central curved portion of the blade member. A fiat surface46 is provided on the inside of lug 43 and the rearmost edge of the lug43 is aligned with the back face 35 of the blade member. The back face35 of the blade member is provided with a recess 47 which has a frontfiat surface 48 (see FIGURES 2 and 4) extending at right angles withrespect to a line bisecting the central curved portion of the blademember. A side wall 49 of the recess opposed to the inner surface 46 ofthe lug 43 slants rearwardly and away from the lug 43 as can be bestseen in FIGURE 4.

Although only one end of the blade member is shown in the drawings, itis believed no further comment is necessary in connection with theopposite end since the two ends of the blade member are identical exceptthat they are a mirror image of each other.

The arm members 32, 32 are also identical except, as in the case of endsof the blade member, they are also a mirror image of each other. Whenassembled rear po-rtions 50, 50 of the arm members 32., 32 aresubstantially parallel. The arm members 32, 32 have converging portions51, 51 so that when assembled, the forward ends of the arm members arein close proximity to each other. The rear portions 50, 50, each ofwhich have an interlocking section 49 formed integrally therewith, curvedownwardly and the rearmost edge of the rear portions 50, 50 preferablyconform in shape to the shape of the convex back face 35 of the blademember so that when the arm members are attached to the blade member,the rear edges of the arm members align with the back face 35 of theblade member.

Each arm member 32 has a flat side surface 52 (see particularly FIGURE3) which engages the end edge surface 46 of the blade member when thearm member is attached to the blade member. A boss 53 is formed on therearmost side surface 52 and has a rear edge conforming with the rearedge of the arm member. The boss 53 has a flat forward edge surface 54for mating engagement with the front fiat surface 48 on the recess 47 asshown in FIG- URE 4. Each arm member 32 has an opening defined byopposed parallel side walls 55, 55 (see FIGURE 3), which are spacedslightly greater than the distance between the parallel side edges 45,45 of the lug 43, and by a beveled front edge 56 slanting rearwardlyaway from the side surface 52. The opening in the arm member is shapedto receive in a snug manner the lug 43 when the side surface 52 of thearm member is in engagement with the end edge sunface 40 of the blademember and forward edge 54 is in engagement with the surface 48 in therecess 47. Preferably the lug 43 has the same thickness as the rearportion of the arm member so that the lug 43 completely fills theopening in the member and the outer surface of the lug 43 is flush withthe outer surface of the arm member as shown in FIGURE 4. The boss 53overlies a rear portion of the opening and thereby has a lug engagingsurface 57 for engagement 'with inner surface 46 of the lug.

Spaced on opposite sides of the opening in the arm member and standingout from the flat side surface 52 are projections 60, 60. Theprojections 60, 60 are located and shaped to fit into grooves 41, 41when the arm member is attached to the blade member and have rearbeveled surfaces 61, 61 slanted forward and away from the side surface52 for engagement with the surfaces 42, 42 of the grooves 41, 41.

The clamping means 33 can include a connecting mechanism which includesbolts well known in the field but is preferably of the type including ahollow box 62 and wedge 63 as shown in FIGURE 1 and described in c0-pending United States application 259,960, filed Feb. 20, 1963, of JohnA. Wilson now Patent No. 3,164,914. By utilizing the clamping mechanismdescribed in the abovementioned application, no bolts whatsoever areused in the slushing scraper and the entire scraper can be knocked downvery easily in the mine with the use of the only tool readily availableto a miner underground, namely a sledge hammer.

To dismantle the completely assembled scraper, as shown in FIGURE 1, thewedge 63 is driven rearwardly with a sledge hammer and removed frombetween the forward ends of the arm members 32, 32. As described in theabove-mentioned application, the hollow box 62 can then be removed fromthe forward ends of the arms permitting the forward ends of the arms tobe separated. Once the hollow box 62 has been removed, the arm memberscan be pivoted about their rear ends since a tapered or radiused spaceis provided between the boss 53 on the arm member and the slanted sidewall 49 of the recess 47 and since mating surfaces 42 and 61, and 44 and56 are beveled. When the forward ends of the arm members 32, 32 areseparated to the extent that the boss 53, on each arm member, engagesthe slanted walls 49 of its respective recess 47, the projections 60, 60are free of the grooves 41, 41 and the forward edge of the lug 43 is outof the opening in the arm member. Each arm member can then be shovedrearwardly with respect to the blade member so that the arm member isseparated entirely from the lug 43 and can be carried away from theblade.

To assemble the slushing scraper, each arm member 32 is brought up tothe blade member from behind at its respective end of the blade memberwith the rear portion 50 extending outwardly at an angle with respect toend edge surface 40 of the blade member so that the boss 53 enters therecess 47 and the outer face of the boss 53 is in engagement with theslanted side wall 49 of the recess. As the boss 53 enters the recess 47,the rear part of the lug 43 enters the forward portion of the opening inthe arm member in front of the boss 53. The forward ends of the armmembers are then swung towards each other until they reach the positionshown in FIGURE 1. As the arm members 32, 32 are pivoted about theirrear ends, the lug 43 on the blade is entirely received in the openingof the arm member, so that the inner surface 46 of the lug engages thelug engaging surface 57 of the boss 53, the projections '60, 60 moveinto the grooves 41, 41 and the flat side surface 52 of each arm membercomes into engagement with the end edge surface 40. The hollow box 62 isthen pushed over the adjacent forward ends of the arm members and thewedge 63 inserted between the forward ends of the arm members and drivenhome to thereby lock all of the components together.

Once the forward ends of the arm members have been secured by theclamping means '33, the rear ends of the arm members are locked to theends of the blade member in such a manner that substantially no play ispermitted between the arm members and the blade members. The forwardpull of the scraper is transmitted to the blade member from the armmember through the engagement of surface 54 of the boss 53 with thesurface 48 in the recess 47 in the back of the blade.

The arm members cannot be separated from the blade member in a'direction perpendicular to the end edge surfaces 40, 40 of the blademember since the lugs 43, 43 are hooked in behind bosses 53, 53 of thearm members. The inner surface 46 of the lug is in the same plane as theend edge surface 40, 40 and the arm members 32, 32 are so shaped thatthe flat side surface 52 of each arm member is held tightly against theend edge 40 of the blade member. Therefore, the lug engaging surface 57of the boss 53 of each arm member is forced into tight engagement withthe inner surface 46 of the lug. Thus, as the arms are brought to theirfinal position, surfaces 40 and 52 act as interengageable fulcrumsurfaces to cause surface 57 to move into tight engagement with surface46 and thereby produce a snug interlock. To ensure snug engagement ofthe parts, the arms 32, 32 are preferably so shaped that they must besprung together to permit the hollow box to be slipped over or removedfrom the ends of the arms. To facilitate the springing of the arms, theforward ends of the arms are provided with aligned openings 59, wherebya bolt can be inserted through the openings 59 when the forward ends ofthe arms have been drawn together by hand and a nut tightened on thebolt to spring the forward ends of the arms closer together.

The rear portions of the arm members cannot twist in a plane parallel tothe end edge surfaces 40 of the blade member due to the fact theparallel side edges 45, 45 of the lugs are closely received betweenparallel side walls 55, 55 of the opening and also because projections60, 60 are received in grooves 41, 41. The arm members are preventedfrom being pushed back off the blade member by engagement of beveledfront edge 56 of the opening engaging the beveled forward edge surface44 of lug 43 and also because of the engagement between the beveledsurfaces 61, 61 of the projections 60, 60 and the inner slanted surfaces42, 42 in the grooves 41, 41.

As indicated, the reception of the projections 60, 60

I in grooves 41, 41 prevents twisting of the arm members with respect tothe blade member and also prevents the arm members from being pushedback off the blade member, but since the reception of the lug 43 in theopening of the arm member also prevents these motions of the arm memberswith respect to the blade member as described above, the scraper willoperate without the projections 60, 60 and the grooves 41, 41.

Since the interlocking elements at each end of the blade member aresymmetrically disposed about the line bisecting the central curvedportion of the blade member, the arm members can be disconnected fromthe blade member when one scraping edge becomes worn and the blademember can be turned end for end and inverted so that the arm membersare connected to the end opposite to which they were previouslyconnected and a new scraping edge is presented along the bottom. Thisoperation can be conveniently performed underground with a sledge hammerand, of course, doubles the life of the blade.

The embodiment of the slushing scraper shown in FIG- URES 5 to 8 issimilar to the embodiment shown in FIGURES 1 to 4. Blade 31a is of thesame shape in 'vertical cross-section as blade member 31 in that it iscurved to present a concave front face 36a, a convex back face 35a, anda pair of forwardly projecting scraping edges 37a, 37a. The blade 31a,which also has opposed flat end edge surfaces 40a, 4011, includes aninterlocking section 38a at each end, one of which is shown in FIGURE 6.Blade 31a does not have a recess in the back face of the blade adjacentlug 43a. Instead the lug 43a, which has side surface 46a and edgesurfaces a, 45a, extends rearwardly from the convex back face 35a sothat its rearmost edge lies behind the convex back face 35a and is notaligned with it as in the case of lug 43a (see FIG- URES 6 and 8).

Arms 32a, 32a, the rear portion 50a of one of which is shown in FIGURES5, 7 and 8, are identical to arm members 32, 32 in that they convergeforward of the blade and are adapted to be secured together by aclamping means at their forward ends. However, at the rear portion ofthe arms, the rearmost edge of interlocking section 49a does not conformto the convex back face 35a of the blade but extends rearwardly of theface 35a when the arm is fixed to the blade. The lug receiving openingin each arm 32a is forward from the rearmost edge of the arm but isidentical in shape to the opening in the arm members 32 and has abeveled front edge sunface 56a and side walls a, 55a. A boss 53a isformed on the side 52a of the arm 32a, but instead of having a fiatforward edge surface as boss 53-, boss 53a has concavely curved frontedge surface 54a, as shown in FIGURE 7, which conforms to the convexback face 35a of the blade. The ends of the blades are provided withbeveled grooves 41a, 41a disposed symmetrically on opposite sides of aline bisecting the central curved portion of the blade and each arm hasa pair of projections a, 60a, for reception in the beveled grooves asdescribed in connection with the previous embodiment.

In the embodiment of the slushing scraper shown in FIGURES 5 to 8, thearms are attached in the same manner described in connection with theprevious embodiment, i.e., to attach the arms to the blade, each arm 32ais brought up to the blade with the rear portion thereof at an angle tothe end edge surface 40a so that the rearmostportion of the lug 43aenters the opening in the arm forward of the boss 53a and the arm ispivoted until the lug 43a fully enters the opening in the arm and thepro jections 60a, 60a enter beveled grooves 41a, 41a. When lug 43aenters the opening, surface 46a engages surface 57a provided by boss53a. The arms are also disassembled in the same manner in that theirforward ends are separated and then the arms are pushed backward withrespect to the blade so that the lugs 43a, 43a, are withdrawn completelyfrom the openings in the arms.

A smooth back type of scraper such as that shown in FIGURES 1 to 4 isdesirable in certain'types of mining operations but the type shown inFIGURES 5 to 8 in which the arms stand out from the back of the blade iscompletely acceptable in many applications and has the advantage thatthe blade is of simpler construction, and

I this is quite important since the blade is the member of the scraperwhich is most frequently replaced.

FIGURES 9 to 13 show another type of slushing scraper of the typeaccording to the present invention in which the arms stand from the backof the blade. The construction of blade 31b.having a front transversesurface 36b and convex back face 35b in this embodiment has aninterlocking section 38b and is merely identical to the construction ofblade 31a of FIGURES 5 to 8, except that lugs 43b, 43b, one of which isshown in FIGURES 9, 10 and 13, are slanted rearwardly away from endedges 40b, 40b of the blade, i.e., lugs 43b, 43b at opposite ends of theblade are slanted towards each other. Lug 43b has edge surfaces 45b,45b, and an outer side surface 43b of each lug 43b commences at surface40b and slants rearwardly away from side surface 52b of arm 32b when thearm is in the attached position. A second side surface 43b" of log 43bis spaced inwardly of surface 43b and is parallel thereto.

As is shown in FIGURE 9, the rear portion of arm 32b, which providesinterlocking section 496, does not conform in outline to the back face35b of the blade but extends rearwardly of the face 35b. A boss 53]; isformed on the side surface 52b of the arm, and as in the case of theembodiment of FIGURES to 8, the boss 5312 has a concavely curved frontedge surface 5415 which conforms to the convex back face 35b of theblade. The arms 32]), 32b per se have no openings therein, but each boss53b includes a bracket section 70 which forms an opening adjacent theside surface 52b and having side walls 55b, 55b for the reception of thelug 4312. Referring particularly to FIGURES 12 and 13 it can be seenthat the bracket section presents a lug engaging surface 71 whichopposes and slants rearwardly away from side surface 52b of the arm atthe same angle as surface 43b. The forward edge of the bracket section70 is beveled at 72 rearwardly and away from side surface 52b as shownin FIGURES 11 and 13. a

Each arm 32b is assembled onto the blade in a manner similar to thatdiscusses in connection with the two previous embodiments. The rearportion of the arm Stlb is brought up to the blade from behind and at anangle with respect to surface 40b of the blade so that the side surface52b is substantially in engagement with the side surface 43b of the lug43b. The rear portion of the arm is then slid forward at said angle withrespect to the surface 40b of the blade so that the lug 43b is receivedin the opening between bracket section 70 and side surface 52b. Becauseof beveled portion 72, the arm can be slid forward at the angle in thismanner until front edge surface 54b of the boss engages the convex backface of the blade. The arm is then pivoted to bring the forward ends ofthe arms together and thereby bringing side surface 43b" into engagementwith lug engaging surface 71 of the bracket section 70, bringing sidesurface 5212 into engagement with surface 40b of the blade and bringingprojections 60b, 60b into beveled grooves 41b, 41b. To disconnect thearm from the blade the forward end of the arm is swung outward and therear portion of the arm is then pushed backward at an anglesubstantially equal to the angle of the lug 43b.

The forward pull of the scraper is transmitted to the blade from thearms through the engagement of the front edge surfaces of the bosses5312 with the convex back face 35b of the blade. The arms cannot beseparated from the blade in a direction perpendicular to the end edgesurface 40b, 40b, because of engagement of surface 43b" of each lug,with lug engaging surface 71 of the bracket section, and the engagementbetween these same two slanted surfaces prevents the arm from beingpushed back off the lug.

The slushing scraper of the embodiment of the invention shown in FIGURES14 to 16 includes a blade 31c of very simple construction having at eachend an interlocking section 380. The blade 310 having a transverse frontsurface 360 and a concave back face 35c is of the same shape in verticalcross-section as the previously discussed blades, but in this embodimentthe blade is formed with openings adjacent its opposite ends 400 and thelugs for reception in the openings are carried by rear portion 500 ofthe arms.

Each arm 320 has on its fiat side surface 52c at the rear portionthereof a boss 53c. The forward edge surface 54c of the boss 53c isconcavely curved to conform to the convex back face 35c. The boss 530has a side surface 530' spaced from the side surface 520 of the arm, anda forwardly projecting lug 430 is formed on the forward edge surface540. The lug 430 has edge surfaces 450, 45c, and :a side surface 430which commences at the side surface 530', and slants forwardly andtowards the side surface 520 of the arm. The lug 430 has a second sidesurface 43c opposing the side surface 520 and sub stantially parallel tothe side surface 430'.

As indicated above, the blade has at each end an opening for thereception of the lug 430. The opening is slot shaped and is defined byend wall surfaces 55c, 55c spaced just slightly greater than the widthof the lug 43c and opposed slanted side surfaces 78 and 79 (see FIG- URE16). The side surface 78 is slanted forwardly and towards the adjacentend of the blade at an angle equal to the slant of side surface 430"with respect to side 520. Side surface 79 slants forwardly and towardsthe adjacent end of the blade at a greater angle than side surface 78 sothat the rear portion of the arm can be turned at an angle with respectto the end edge surface of the blade when the arm is being attached ordisassembled. The end edge surface of the blade is beveled towards theback face of the blade at 80 adjacent the boss 530 to permit the turningof the arm with respect to the blade when lug 430 is received in theopening of the blade during the assembling or disassembling operation.

The movements of each of the arms 32c, 320 during the assembling ordisassembling operation are the same as described in connection with theembodiment of the invention shown in FIGURES 9 to 13 and will not bedescribed again at this time. When the forward ends of the arms aresecured together the arms cannot be separated from the blade in adirection perpendicular to the side surface 52c because of theengagement of surfaces 430" and 78 and the engagement of these same twoslanted surfaces prevents the arms from being pushed back off the blade.The other forces which occur between the arms and the blade are takenupas described previously in connection with the other embodiments ofthe invention.

Referring now to the embodiment of the invention shown in FIGURES 17 to20, it will be noted that this embodiment provides for a smooth backtype of scraper having an interlocking section 38d at opposite ends ofthe blade, but that it differs from the embodiment shown in FIGURES 1 to4 in that the lug receiving openings are in the blade and the lugs arecarried by the arms. As in the previously discussed embodiments theblade 31d has in vertical cross section a curved central portion andcontiguous leg portions (see particularly FIGURE 18). At opposite endsof front transverse surface 36d a web member 86 extends between the legportions 34d, 34d and is flush at one side with end edge surface 40d ofthe blade. Rear edge 87 of web member 86 is spaced from the curvedcentral portion of the blade and slants rearwardly and away from the endedge surface 40d (see FIGURES 18 and 20). At each end of the blade thereis provided a lug receiving opening which is defined by opposed end wallsurfaces 88 and 89 and opposed side surfaces 90 and 91 (see FIGURES 18and 20). The surface 91 which is spaced inwardly from the edge surface40d slants rearwardly and away from surface 40d While side surface 90 issubstantially parallel to surface 40'd. As in the case of the firstdescribed embodiment, the rearmost edges of the arms 32d, $20!, the rearportion 500! of one of which is shown in FIGURES 17 and 19, conform inshape to the convex back face 35d of the blade so that these edges arealigned with the back face when the arms are attached to the blade. Atthe rear end of each arm, a step portion is formed providing the lugs(FIGURES 19 and 20). Each arm 32d has a flat side surface 52d and anoutstanding part or boss 53d formed thereon. The boss 53d has an outlineof the same shape as the opening formed between Web member 86 and thecurved central portion of the blade, and a forward edge surface 54d ofthe boss is beveled rearwardly and away from side surface 520. formating engagement with rear edge 87 of web member 86. The boss 53d is ofthe same thickness as web members 86, and has a flat outer surface whichis, therefore, flush with the inner surface of the web when the arm isfastened to the blade. Lug 43d is, which has edge surfaces 45d, 45d,formed on the flat outer surface of boss 53d, and as can be seen fromFIG- URES 19 and 20 the forward edge surface of the lug is beveled atthe same angle as the forward edge surface 54d of boss 53d and is acontinuation of the beveled forward edge surface 54d. The lug 43d has anouter side surface which is parallel to the side surface 52d and spacedtherefrom a distance just slightly less than the distance between sidesurface 90 of the opening and end surface 40d of the blade. Rearmostsurface 43d" of the lug 43d (see FIGURE 20) is slanted rearwardly andaway from side surface 52d at an angle approximately equal to the slantof side surface 91 of the opening and is arranged to be immediatelyadjacent the side surface 91 when side surface 52d of the arm engagesend surface 40d of the blade. The angle of bevel of the front edgesurface 54d and the front edge surface of the lug 43d is greater withrespect to side surface 520 as can be seen in FIG- URE 20.

When the arms are being connected to the end of the blade, the lug 43dof interlocking section 49d of each arm is inserted into the spacebetween web member 86 and the curved central portion of the plate andduring this operation the forward ends of the arms are kept separated asin the previous cases so that the side surfaces 52d, 52d of each arm areat an angle with respect to the end edge surfaces 40d, 40d of the blade.After the lugs 43d of each arm is inserted into the space behind webmember 86, each arm is turned about its rear portion so that the forwardends of the arms come together and side surface 52d moves toward endedge surface 40d. At the same time the rear portions of the arms arepushed rearwardly a small amount which moves boss 53d into the spacebehind web member 96 and lug 43d into the opening in the blade.Eventually side surface 52d comes into complete engagement with end edgesurface 40d, boss 53d is completely received in the space between theweb member 86 and the curved central portion of the blade and the lug isreceived in the opening in the blade as shown in FIGURE 20 as theforward ends come to their clamping position. The required movements toseparate the arms from the blade are, of course, the exact reverse ofthose just described.

As indicated above, the embodiment of FIGURES 17 to 20 is a smooth backtype scraper as is the embodiment of FIGURES l to 4. In some respectsthe blade construction of the embodiment of FIGURES 17 to 20 is simpler,but it has the disadvantage of the connecting means being stressed to agreater extent than all of the previously described embodiments. Unlikeall of the previously described embodiments, the pulling force is nottransmitted to the blade by engagement of the boss with the back surfaceof the blade. In this last embodiment, the pulling force is transmittedto the blade through the engagement of beveled surface 54d of the boss53d with beveled surface 87. Because surfaces 54d and 87 are at an anglewith respect to the direction of pull, a component of force is developedwhich tends to separate the arm from the blade in a directionperpendicular to the side surface 52d. This force is taken up byengagement of surface 43d" with side surface 91 of the opening, which,of course, produces additional stresses in the lug 43a.

The reception of the shoulders of the boss in the shoulders surroundingthe opening formed by web 86 and the curved central portion prevents thearm from twisting in a plane parallel to side surface 52d, and theengagement of surfaces 43d" and 91 prevent the arm from being pushedback off the blade.

It can be readily appreciated from the above description that presentinvention provides for a slushing scraper which can be easily assembledand disassembled. Since it can be easily disassembled and reassembledunderground, transportation of the scraper is facilitated or any partcan be readily replaced or taken to the surface :for repair. Moreover,with the constructions described, the blade can be easily invertedunderground so that a new scraping edge is presented when the first edgebecomes worn.

We claim:

1. A slushing scraper comprising (a) a blade having (i) a fronttransverse surface, and

(ii) a first interlocking section integrally formed at each end thereof,

(b) a pair of arms each having (i) a forward end portion, and

(ii) a rear end portion,

(c) each said rear end portion having a second interlocking sectionformed integrally therewith,

(d) each of said first sections being engageable with one of said secondsections to provide two pairs of interlocking sections for locking saidblade and arms together in an interlocking position,

(e) means for clamping said blade between said rear end portions of saidarms comprising (i) a fulcrum surface defined by each of saidinterlocking sections and angularly disposed relative to said frontsurface,

(ii) said fulcrum surfaces of each said pair of sections beingengageable with each other to define a clamping position of said armsand blade,

(iii) a lug on one of said sections of each pair thereof having asurface angularly disposed relative to said front surface,

(iv) a wall surface engageable with said lug surface on the othersection of each pair thereof, and

(v) a clamping fixture for holding said front end portions togetherthereby to hold said fulcrum surfaces in engagement and said lug andwall surfaces in engagement,

(f) means for preventing movement of said blade in a first directionforwardly and rearwardly of said arms when the arms and blade are in theclamping position comprising (i) a first pair of opposed shoulders onone of said sections of each pair'thereof each having a surface lying ina plane intersected by any plane perpendicular to said front surface,and

(ii) a surface engageable with each said shoulder surface on the otherof said sections of each pair thereof,

(g) and means for preventing movement of said blade with respect to saidarms in a direction perpendicular to said first direction comprising (i)a second pair of opposed shoulders on one of said sections of each pairthereof each having a surface lying in a plane intersected by said firstshoulder surface planes, and

(ii) a surface engageable with each said second shoulder surface on theother of said sections of each pair thereof,

(h) each said arm having free swinging movement in a direction towardsand away from said blade on disengagement of said clamping fixture fromsaid arms,

(i) said blade and arms in said clamping position having said fulcrumsurfaces in engagement, said lug and wall surfaces in engagement, andsaid shoulder surfaces and said shoulder engaging surfaces inengagement.

2. A slushing scraper as defined in claim 1, wherein the rear endportion of each arm has a side surface and said blade has an end surfaceat each end thereof, said side surface of each arm and one of said endsurfaces providing said fulcrum surfaces of each of said pair ofinterlocking sections, wherein said lug is formed integral 1y on andprojects rearwardly from said blade, and wherein each said arm has abracket formed on said side surface thereof and having a front surfaceproviding one of the surfaces engageable with one of said first pair ofshoulders, said front surface of said bracket being engageable behindsaid blade, said bracket providing said wall surface and defining a lugreceiving opening between said rear portion of said each arm and saidwall, said wall and said lug in said clamping position slantingrearwardly and away from said side surface of said arm.

3. A slushing scraper as defined in claim 2, wherein the shoulders ofsaid means for preventing movement of the blade in a directionperpendicular to said first direction at least in part compriseprojections on said side surface of each arm, each projection having abeveled rear surface slanting forwardly and away from said side surface,aid wherein said second shoulder engaging surfaces are at least in partprovided in the front surface of said blade by beveled grooves at bothends thereof slanting rearwardly to said end surfaces for reception ofsaid projections.

4. A slushing scraper as defined in claim 2, wherein said blade has acentral curved portion in vertical crosssection so that said front faceis concave and the rear face is convex.

5. A slushing scraper as defined in claim 4, wherein the forward edgesof the brackets are concave to conform to the rear face of the blade.

6. A slushing scraper as defined in claim 4, wherein the blade has twoside edges forming forwardly projecting scraping edges, and saidinterlocking sections are disposed symmetrically about a line bisectingsaid curved portion.

7. The slushing scraper as defined in claim 1, wherein the rear endportion of each arm has a side surface and said blade has an end surfaceat each end thereof, said side surface of each arm and one of said endsurfaces providing said fulcrum surfaces of each pair of interlockingsections, and wherein each arm has a boss formed on the side surface andhaving a front face providing one of the surfaces engageable with one ofsaid first pair of shoulders, said front face being engageable behindsaid blade, wherein said lug is formed integrally on the front face ofsaid boss, and wherein said blade has a lug receiving opening extendingthereto from behind, said opening being defined in part by said wallsurface, said wall and lug in said second position slanting forwardlytoward said side surface of said arm.

8. A slushing scraper as defined in claim 7 wherein said blade has acentral curved portion in vertical crosssection so that said front faceis concave and the rear face is convex.

9. A slushing scraper as defined in claim 8 wherein the front faces ofthe bosses are concave to conform to the rear face of the blade.

10. A slushing scraper as defined in claim 8, wherein the blade has twoside edges forming forwardly projecting scraping edges, and saidinterlocking sections are disposed symmetrically about a line bisectingsaid curved portion.

11. A slushing scraper as defined in claim 1, wherein said lug isincluded in a stepped portion on one of said sections of each pair ofinterlocking sections, and wherein the other of said sections isprovided with a stepped portion receiving opening being defined at leastin part by shoulders of said first and second pairs, said steppedportion having faces providing said shoulder engaging surfaces.

12. A slushing scraper as defined in claim 11, wherein the rear endportion of each arm has a side surface and said blade has an end surfaceat each end thereof, said side surface of each arm and one of said endsurfaces providing said fulcrum surfaces of each pair of interlockingsections, wherein said stepped portion includes an outstanding part onsaid side surf-ace of the arm with the lug being laterally spaced fromsaid side surface and projecting rearwardly from said outstanding part,and wherein said opening is formed in said end surface of said blade.

13. A slushing scraper as define-d in claim 12, wherein the blade has acurved central portion and two contiguous leg portions in cross section,wherein a web member at each end of said blade extends between the legportions and provides in part said end surface of said blade, each webbeing spaced from said curved central portion to form said opening insaid end surface, wherein said outstanding part has an outline formating reception 12. in said opening formed by said web and said curvedcentral portion, and wherein said curved central portion of said bladehas a rearwardly extending, lug receiving opening in said front surfaceand inward from the end of said blade, said lug receiving opening beingdefined in part by said lug engaging wall surface.

14. A slushing scraper as defined in claim 1, wherein the rear endportion of each arm has a side surface and said blade has an end surfaceat each end thereof, wherein said each arm has an outstanding part onsaid side surface, said outstanding part having a front face providingone of the surfaces engageable with one of said first pair of shoulders,said front face being engageable behind said blade in said clampingposition, and wherein the shoulders of said means for preventingmovement of the blade in a direction perpendicular to said firstdirection at least in part further comprise projections on said sidesurface of said each arm, said second shoulder engaging surfaces beingin part provided by projection receiving grooves in said end surface ofsaid blade.

15. A slushing scraper as defined in claim 1, wherein each rear endportion of said arms has inner and outer side surfaces and is providedwith a lug receiving opening defined in part by surfaces providing saidsecond pair of shoulders and extending between and being substantiallyperpendicular to said side surfaces, wherein said lug is integrallyformed on said blade member and has opposite parallel side facesproviding said second shoulder engaging surfaces, and wherein a boss isformed on said side surface of the arm, said boss partially overlyingsaid opening to define said lug engaging wall surface.

16. A slushing scraper, comprising a scraper blade member having frontand rear faces, end surfaces and a scraping side edge, a pair of armmembers having side surfaces at rear portions thereof, and locking meansfor separably securing said arm members to said blade member with saidside surfaces of each of said arm members in engagement with one of saidend surfaces, said locking means including a boss formed on the sidesurface of each arm member and having a forward edge for engagement withsaid rear face of said blade, and a pair of lugs formed at opposite endsof the blade and projecting rearwardly from said rear face, each lughaving a boss engaging side surface and a beveled forward edge spacedforwardly from said rear face and slanting rearwardly from the endsurface of the blade, said arm members each having an opening thereinfor reception of one of the lugs when said side surfaces are inengagement with said end surfaces, each boss having a portion overlyinga rear portion of the opening for engagement with the boss engagingsurface of the lug when the lug is received in the opening to preventseparation of said arm members from said blade member in a directionperpendicular to said side surfaces, said openings having a beveledfront edge slanting rearwardly away from the side surfaces forengagement with said beveled forward edge of the lug.

17. A slushing scraper comprising a scraper blade memher having frontand rear faces, end surfaces and a scraping side edge, a pair of armmembers each having a forwardly projecting portion and a rear portionhaving a side surface, and locking means for separably securing said armmembers to said blade members together with the side surfaces inengagement with the end surfaces, said locking means including a bossformed on the side surface of each arm member and having a forward edgesurface for engagement with said rear face of said blade, a lug formedat each end of the blade and projecting rearwardly from said rear face,said lugs having a boss engaging side surface, each of said arm membershaving an opening therein for reception of one of said lugs when itsside surface is in engagement with one of the end surfaces, each bosshaving a portion thereof overlying a rear portion of said opening forengagement with the boss engaging surface of said lug when said lug isreceived in said opening to thereby prevent separation of said armmembers from said blade member in a direction perpendicular to said sidesurfaces, the front surface of said blade having beveled grooves at bothend surfaces, said grooves having an inner surface slanting rearwardlyto the respective end surface, and a projection on the side surface ofeach arm member for reception in one of the grooves and having a rearbeveled surface slanting forward and away from said side surface forengagement with the slanting surface of the grooves when said sidesurfaces are in engagement with said end surfaces.

18. A slushing scraper comprising a scraper blade having front and rearfaces, end surfaces and a forward projecting scraping edge along a sideedge, two arm members having normally juxtaposed forward ends and rearside surfaces, and locking means for separably securing said arm membersto said blade with the side surface of each arm in engagement with oneof the end surfaces of said blade, said locking means including a bosson said surface of each arm having a forward edge for engagement withthe rear face of said blade, a rearwardly projecting lug formed at eachend of the blade, each lug having a boss engaging side surface in theplane of the adjacent end surface of the blade, and a beveled forwardedge spaced forwardly from said rear face and slanting rearwardly fromthe adjacent end surface, the arm members each having an opening thereinfor reception of said lug when said side surfaces are in engagement withsaid end surfaces, the boss on the side surface of each arm memberhaving a portion thereof overlying a rear portion of said opening forengagement with the boss engaging portion of the lug when said lug isreceived in said opening to thereby prevent separation of said armmembers in a direction perpendicular to said side surfaces, said openinghaving a beveled front edge slanting rearwardly away from the sidesurface for engagement with the beveled forward edge of said lug, and aprojection on the side surface of each arm having a rear beveled surfaceslanting forward and away from said side surface, the front face of theblade having beveled grooves in both end surfaces for reception of theprojections, said grooves having inner surfaces slanting rearwardly tothe end surfaces for engagement with the beveled surfaces of theprojections when said side surfaces are in engagement with said endsurfaces.

19. A slushing scraper as defined in claim 18 wherein said blade has acentral curved portion in vertical crosssection so that said front faceis concave and said rear face in convex.

20. A slushing scraper as defined in claim 19, wherein said arm membershave rear edges extending rearwardly of said rear face when said armmembers are separably secured to said blade and the forward edge of saidboss is concavely curved to conform to the rear convex face of theblade.

21. A slushing scraper as defined in claim 19, wherein the arm memberand the boss have aligned rear edges conforming in outline to the curvedcentral portion of the blade, and the rear face of the blade is providedwith a recess adjacent said lug for the reception of said boss with therear edges of the boss and arm member aligned With the back face of theblade.

22. A slushing scraper as defined in claim 19, wherein said blade hastwo side edges forming forwardly projecting scraping edges, and saidlocking means is disposed symmetrically about a line bisecting saidcurved portion.

References Cited UNITED STATES PATENTS 2,626,471 1/ 1953 Whisler 37-1472,716,824 9/1955 Francis 37147 2,743,540 5/1956 Whisler 37-147 2,763,0749/1956 Whisler 37147 ABRAHAM G. STONE, Primary Examiner.

ANTONIO F. GUIDA, Examiner.

A. E. KOPECKI, Assistant Examiner-

1. A SLUSHING SCRAPER COMPRISING (A) A BLADE HAVING (I) A FRONTTRANSVERSE SURFACE, AND (II) A FIRST INTERLOCKING SECTION INTEGRALLYFORMED AT EACH END THEREOF, (B) A PAIR OF ARMS EACH HAVING (I) A FORWARDEND PORTION, AND (II) A REAR END PORTION, (C) EACH SAID REAR END PORTIONHAVING A SECOND INTERLOCKING SECTION FORMED INTEGRALLY THEREWITH, (D)EACH FIRST SECTIONS BEING ENGAGEABLE WITH ONE OF SAID SECOND SECTIONS TOPROVIDE TWO PAIRS OF INTERLOCKING SECTIONS FOR LOCKING SAID BLADE ANDARMS TOGETHER IN AN INTERLOCKING POSITION, (E) MEANS FOR CLAMPING SAIDBLADE BETWEEN SAID REAR END PORTIONS OF SAID ARMS COMPRISING (I) AFULCRUM SURFACE DEFINED BY EACH OF SAID INTERLOCKING SECTIONS ANDANGULARLY DISPOSED RELATIVE TO SAID FRONT SURFACE, (II) SAID FULCRUMSURFACES OF EACH OF SAID PAIR OF SECTIONS BEING ENGAGEABLE WITH EACHOTHER TO DEFINE A CLAMPING POSITION OF SAID ARMS AND BLADE, (III) A LUGON ONE OF SAID SECTIONS OF EACH PAIR THEREOF HAVING A SURFACE ANGULARLYDISPOSED RELATIVE TO SAID FRONT SURFACE, (IV) A WALL SURFACE ENGAGEABLEWITH SAID LUG SURFACE ON THE OTHER SECTION OF EACH PAIR THEREOF, AND (V)A CLAMPING FIXTURE FOR HOLDING SAID FRONT END PORTIONS TOGETHER THEREBYTO HOLD SAID FULCRUM SURFACES IN ENGAGEMENT AND SAID LUG AND WALLSURFACES IN ENGAGEMENT, (F) MEANS FOR PREVENTING MOVEMENT OF SAID BLADEIN A FIRST DIRECTION FORWARDLY AND REARWARDLY OF SAID ARMS WHEN THE ARMSAND BLADE ARE IN THE CLAMPING POSITION COMPRISING (I) A FIRST PAIR OFOPPOSED SHOULDERS ON ONE OF SAID SECTIONS OF EACH PAIR THEREOF EACHHAVING A SURFACE LYING IN A PLANE INTERSECTED BY ANY PLANE PERPENDICULARTO SAID FRONT SURFACE, AND (II) A SURFACE ENGAGEABLE WITH EACH SAIDSHOULDER SURFACE ON THE OTHER OF SAID SECTIONS OF EACH PAIR THEREOF, (G)AND MEANS FOR PREVENTING MOVEMENT OF SAID BLADE WITH RESPECT TO SAIDARMS IN A DIRECTION PERPENDICULAR TO SAID FIRST DIRECTION COMPRISING (I)A SECOND PAIR OF OPPOSED SHOULDERS ON ONE OF SAID SECTIONS OF EACH PAIRTHEREOF EACH HAVING A SURFACE LYING IN A PLANE INTERSECTED BY SAID FIRSTSHOULDERS SURFACE PLANES, AND (II) A SURFACE ENGAGEABLE WITH EACH SAIDSECOND SHOULDER SURFACE ON THE OTHER OF SAID SECTIONS OF EACH PAIRTHEREOF, (H) EACH SAID ARM HAVING FREE SWINGING MOVEMENT IN A DIRECTIONTOWARDS AND AWAY FROM SAID BLADE ON DISENGAGEMENT TO SAID CLAMPINGFIXTURE FROM SAID ARMS, (I) SAID BLADE AND ARMS IN SAID CLAMPINGPOSITION HAVING SAID FULCRUM SURFACES IN ENGAGEMENT, SAID LUG AND WALLSURFACES IN ENGAGEMENT, AND SAID SHOULDER SURFACES AND SAID SHOULDERENGAGING SURFACES IN ENGAGEMENT.